Ice mold with spring tensioned diaphragm



une 5, 1945. l.. l. MALLARD ICE MOLD WITH SPRING TENSIONED DIAHRAGM l', l lia) \\\\\\\\\\\`\\\\\\l 2 l r l n r Patented June 5, 1945 UNITED :STATES PATENT OFFICE ICE MOLD SPRING TENSIONED DIAPHIRAGM Logan Mallard, nrfolk. Ya.

Application December 4, 1941, Seral No. 421,641

6 Claims. (Cl. -.62.108.5)

This invention relates to refrigeration, and particularly to ice forming apparatus and means for releasing ice from the mold or other device kin which it is frozen.

The apparatus herein disclosed is primarily adapted for use with ice molds of the 'type disclosed in my copending applications, Ser. Nos. 290,479 and 421,648, filed August 16, 1939 and December 4, 194i, respectively, and wherein the `ice mass is dislodged or ejected from its mold by means of expansible gases entra-pped in an er:i pansion chamber vpreferably--located in the base of lthe mold, the gases contracting or becoming more dense upon a drop in temperature 'and eX- panding and acting -on a iexible or lmovable Idiaphragm beneath the ice mass when subjected to arise in temperature, for example, when the mold 'is removed its freezing chamber and subjected to 'roo-m or .atmospheric temperature.

Gases having yarying characteristics respect to boiling point, coenicient of expansion :and other factors used in .molds :of the type disclosed in my above noted applications. 'Thus in certain instances the gas used may expand suti'l'ciently when 4subjected to room `ternpenat/ure to move the exi-ble base or diaphragm upwardly but may not condense .sufliciently during rreezing process to permit the diaphragm to flex downwardly. In other instances, pressure tolerance .or range between the `point lat which the diaphragm will flex upwardly and the 'point which `will release the diaphragm ,for downward movement may be relatively narrow so that consistent operation .of the diaphragm becomes doubtful.. Also in large molds such .as those used in vice manufacturing plants," the 'base .of the mold which may constitute the ejecting or disl-odging diaphragm must be of relatively :great and therefore necessitates relatively heavy ,gauge metal, and this coupled with the fact that a certain amount of residual pressure may remain in the pressure chamber of the mold, sometimes results in the diaphragm remaining 1in its"up position.

An object of the present invention,therefore. is to provide means which will .insure consistent operation ci molds of the 4gas pressure iceeject ing type. More specically., the invention provides .means which will act to return the .diaphragm or other movable ice-ejecting member at the base of the .mold to .its down position after being acted upon by the expanded gases, and which means may be selected or adjusted in acccrdance with the particular characteristics of the gas used in the expansion chamber.

lThe aforegong and other objects and advantages become Aappanent in View -of 'the following description taken in conjunction with the lmold of the type utilizing air in the expansion chamber having 'the present inventiony embodied therein;

Fig. 4 is a top plan view-'of Fig. 3;

Fig. 5 is a transverse vertical section of a multiple lcompartment or grid section mold yembodying 'the invention.

Referring to the 'drawing in rdetail and iirstto Figs. 1 and 2, a mold -is generally 'indicated at It and comprising Aan inner container or mold proper -I I and 'an outer receptacle or shell I2, said inner and outer containers being united at their top `margins by an interlocking joint I3, which 'may be 'sealed by beading, soldering, welding or the like. The relative dimensions of the 'inner and outer containers `are such as to providefan expansion chamber 'I4 in the bottom of the mold adapted to be 'lled or loaded with a suitable gaseous medium, suchvas a refrigerant gas having characteristics which will adapt it for the 'intended purpose. The bottom wall of the mold proper Il is preferably constructed as a flexible diaphragm 1I5 which is acted upon by the gas when the latter expands .and is caused to ilex upwardly and eject the ice mass from the mold.

The bottom of the outer container I2 and the inner container I l are provided with lugs lI-B and I1 to which are connected the .Opposite ends of a spring I8. This spring should be of sufficient strength to rpull the diaphragm`l5 from its upper or dotted line position to the yfull line position indicated .in Fig. .1, :and at the same time it should permit upward movement of the diaphragm when the vlatter is subjected to pressure of the expandinggas within the chamber I4. Certain types of gases :may require .heavier .springs than others. Also, ,a gas .may .be selected having a coeicient of expansion such thateven when the mold is in its freezing chamber, the pressure would be suflicient to prevent downward movement of the v diaphragm unless the latter were aided by the spring. The .strength of the Vspring I8 maybe such 4as to vinsure downward movement of the diaphragm l5 overa relatively wide range of ice-ejecting diaphragm may be operated "by air.

In this instance the mold is generally indicated at and comprises an inner container 2| and an outer container 22 provided with a flexible bottom or diaphragm 23. The containers are of such relative dimensions as to provide an expansion chamber 24 in the base of the mold, the wall of which is formed with a series of vents or breather openings 25, as disclosed in my co-pending application, Serial No. 421,648, above noted. A spring 26 is connected at one end to the bottom wall or diaphragm 23 and its opposite end is anchored to the bottom of the outer container 22.

The mold shown in Figs. 3 and 4 operates substantially as follows:

The vents or openings are of such size as to permit air to leak or breathe into the pressure chamber 24'. This intake of air may be gradual and take place during the initial freezing operation. Sometimes the breather vents 25 may become clogged or occluded by frozen moisture after a certain period of time, butin such instances occlusion does not take place until after the pressure chamber 24 has taken in the required quantity of air. When the mold is taken from its freezing chamber and subjected to a rise in temperature, the air in the chamber 24is caused to expand and exert pressure on the diaphragm 23 and thereby eject the ice mass or block from the mold proper 2|. The spring 26 insures downward movement of the diaphragm 23 when a predetermined pressure is reached in chamber 24,

Fig. 5 shows a mold of the multiple cell or grid type comprising an outer casing 30 and inner casing or mold proper 3|-, the outer and inner containers being joined and sealed at their upper marginal edges and which edges are preferably formed with coacting interlocking flanges. The inner container 3| is formed with a series of freezing compartments 3.2, each having a flexible.

bottom 01' diaphragm 33, 33. Upstanding' brackets 34 and 34' are anchored to the floor of the outer container and have pivoted thereto bellcrank levers 35 and 35 which at their inner or lower ends are connected by a spring 36, the opposite ends of the levers being pivotally connected to the diaphragms 33 and 33.

The operation 0f this form of mold is essentially the same as that of the molds I0 and 2,

' the difference being that in this instance one spring may serve any number of ice molds or freezing compartments. l

'I'he springs I8, 26 or 36 have functions other than simply to retract the ice-ejecting diaphragm or movable bottom of the mold cavity. For example, they enable the satisfactory use of gases which might not wholly liquefy within a certain tempera-ture range, such as sulphur dioxide which at 22 F. has a remaining or residual pressure of approximately 31/3 pounds per square inch. By the use of a spring of a certain predetermined strength or tension, the downward pull of the diaphragm will become effective although only a partial change in the state of the gas has occurred; and upon removal of the mold from its freezing'chamber, the spring will'still permit the diaphragm to eject the ice by the kinetic action of the gas. Thus, the gas expansion chamber may be loaded at substantial saturation of the gas and a spring used Which Will hold the diaphragm downwardly with a pull just suilicient to carry it beyond the center of its normal plane in a downward direction.

If desirable or found necessary, the springs I8, 26 or 36 may be provided with a corrosionresistant coating to insure long life and constant tension.

It will be understood that certain limited changes in construction and design of lthe improved mold may be made without departing from the spirit or scope of the invention as deflned'in the copending claims.

What is claimed is:v

1. In an ice mold, a mold proper having a mold cavity and a flexible diaphragm at the base thereof, an outer container or receptacle for said mold proper spaced from the latter and defining in conjunction therewith an expansion chamber adapted to contain an expansible gas or fluid medium which when subjected to a temperature rise expands and exerts pressure on said diaphragm and flexes it upwardly to eject an ice block or mass from the mold cavity, and resilient means connecting said diaphragm to the outer container and normally urging the diaphragm to its down position.

2. An ice mold comprising an inner container having a mold cavity and outer container spaced from the inner container and providing an expansion chamber therebetween, said expansion chamber containing a gaseous or fluid medium expansble and contractible in volume when subjected to varying degrees of temperatures, the bottom of the mold cavity being flexible to provide an ice ejecting diaphragm, and a spring connecting the bottom of the inner container with the bottom of the outer container and normally urging the said diaphragm to its down" position.

3. In combination with a freezing chamber, an ice mold comprising a mold proper having a mold cavity with a flexible bottom wall providing an ice-ejecting diaphragm and an outer wall or shell surrounding the base of the said mold and providing an expansion chamber beneath said diaphragm, said shell being formed with one or more vents functioning as breathing openings to admit air into the said chamber as the volume of the air is reduced during the `ice freezing period while said mold is in its freezing chamber, removal of the mold from its freezing chamber subjecting the air to a rise in temperature and causing the air to expand and actuate said diaphragm, and resilient means interconnecting said diaphragm with said shell and normally urging the diaphragm to its -down position.

4. An ice mold comprising an inner container having downwardly sloping walls and an outer container joined thereto adjacent its top margin to provide a sealed chamber therebetween, a flexible diaphragm in the bottom o1' said inner container, and resilient retardingmeans connecting the bottom of said outer container with the under surface of said diaphragm.

5. A device of the character described comprising a wall having a pocket formed vtherein for receiving water to be frozen into a unit oi' ice, the bottom wall of said pocket being deformable; means cooperating with said bottom to form a chamber; and a body of fluid confined in said chamber in position to react against said deformable bottom wall; said means being constructed and arranged to transfer heat from an external source to said fluid and said fluid being of such character and being present in such amount as to exert, upon a rise in temperature thereof, a force upon said bottom suflicient to move the from said cavity, the structure providing an eX- pansion chamber for an expansible fluid capable of moving said bottom to release ice upon the expansion of said uid due to rise in temperature.

and resilient means normally urging said bottom toward non-ice-releasing position.

' LOGAN L. MALLARD. 

